Automatic screw-threading machine



Sept. 2?; 1931. J. F. ARNOLD 1,825,171

' AUTOMATIC SCREW. mnmnme MACHINE Filed June 22, 1928 4 sheets-sheet 1 Sept. 29, 1931 J. F. ARNOLD I I b 5 AUTOM ATIC SCREW THREADING MACHINE Filed June 22, 1928 4 Sheets-Sheet 2 fir/laid Sept. 29, 1931.

J. F. ARNOLD 1,825,171

AUTOMATI C SCREW THREADING MACHI NE F:i.led June 22 1928 4 Sheets-Sheet s was? " JazzZflhza Sept. 29,1931. J. F. ARNOLD 1,825,171

AUTOMATIC SCREW THREADING MACHINE Filed June 22, 1928 4 Sheets-Sheet 4 Jean F/Zr/wZd Ill/VE/I/ r0 Patented Sept. 29,, 1931 UNITED STATES- mm rnancors kimono, or rams, raancn AUTOMATIC SCBEW-THREADING MAGHIN E Application filed June 22,4928, Serial No. 287,543, and in France March 26, 1928.

The present invention relates to screw cutting machines particularly adapted for forming screw threads and points uponv wood screw blanks having for its principal object 6 to provide a machine for the automatic han-' dling of the screw blanks and completing the wood screw therefrom in order to increase production and reduce .the cost of wood screws-thereby rendering the machine commercially desirable.

With the above and other objects in view, which will be apparent as the description continues, the machine maybe said to consist of a screw blank feeding mechanism, a plurality of rotatable chucks for engaging and holding screw blanks which have been fed thereto by the said feeding mechanism, a plurality of tools corresponding in number to the chucks so employed in order to out the desired screw threads. upon the blank and also form a point for the screw and a suitable re leasing mechanism, whereby the screws, when completed, may be released from the chucks which support the-same and all of said mechanisms being operatively connected to a single drive shaft whereby they will be automatically operated to perform their work at the desired time in order that screw blanks may be fed to themachine and completed therein without. any manual aid after the ma chine has been once set in motion.

The appended drawings which are given by way of example show a constructional'form of the said invention and represent an automatic machine for the manufacture of four screws at a time.

Fig. 1 is a general plan View of the machine, Fig. 2 is a longitudinal view. without the blank-feeding device. Fig. 3 is a transverse view on a larger scale of the supportsfor the blanks. Fig. 3 is a detail sectional view. Fig. 4 is'a front view of the tool'carrying block on a larger scale. Figs. 5 5 and 6 are front and side views of a blank--- feeding device. Fig. 7 shows thedelivery of a blankbefore a chuck. Fig. 8 shows the blank in the chuck. Fig. 9 shows thefposition of the tool whenseparated from the blank.

to Fig. 10 shows the tool engaged with the blank in order to form the point of the screw. Fig. 11 shows the screw-cutting operation.

1 in the driving shaft of the machine, which is rotated by a suitable mechanism provided with coupling means. The said shaft is 5 mounted in two bearings 2 and 3 (Fig. 1) and drives the auxiliary shafts 45(i7 by means of the worm 8 engaging the worm wheel 9 (Fig. 2). The saidshai'ts rotate at a speed determined by the time necessary for 0 the screw-cutting operation, and are connected. together by the bevel gearing l0l1-l2 (Fig. l) and are mounted in the bearings 13l4--1516l718 secured to the base plate 19 (Fig. 2), not shown in Fig. 1. 66 The movement of the shaft 1 is transmitted to preferably four chucks three of which are shown inthe drawings at 2021-22, by the cone clutch 24 and the central pinion 25 keyed to the shaft of the clutch and engaged with both pinions mounted on the shafts of the respective chucks The said chucks receive the blanks for the screw cutting. The cone clutch 24 is controlled by the cam 26 keyed to the shaft 5 and acting on the lever 27 which is pivoted to the shaft 28 and controls the fork 29 disposed inthe groove 30. The said clutch is regulated by the device 31 which al lows of bending the lever 27. The chucks shown are mounted on the shafts 3233-,3-l which rotate in the stocks 3637-38.

The chucks themselves each consist of a hollow head (Fig. 2) to which are pivoted two levers 40 and 41 terminated at the front by two jaws and at the rear by two rollers which when separated will close thesaid jaws upon the screw blank. The pivoted levers 40-44. are urged to the rear by a spring, not shown.

-The rollers are separated by the lengthwise displacement of sleeves 42 comprising a tapered part on which the said rollers can mount. The sleeves 42 are controlled by a double fork 43 coacting with the grooves 44 of the sleeves; said double fork assures an approved rigidity to the sleeves when connected, and is cont-rolled by the lever 45 (Fig.

1) acting on the cam 46 keyed to the shaft 5.

Infront of the said chucks are disposed a palr of supporting members as indicated at a 49-50. respectively (Fi 2 1'30.

adapted to hold the blank and to prevent it from bending by the pressure of the tool during the work. The said supports are movable and can thus be withdrawn when the blanks are placed in the chucks, this being performed in the following manner. The said supports are connected together in pairs by two sliding members 51 and 52 (Figs. 3 and 3 which are mounted by dovetails in the guides 53-54 secured to the machine. The guide 52 is cut out to permit the motion of-the arms 47 and 48 carrying the supports 47-48. The two sliding members are given an opposite reciprocating motion in the vertical direction, this being controlled by a lever 55 a :tuated by the cam 56 on the shaft 6. The said lever pivots on a stationary point 57 and is connected with the guides 5l52 by the links 5; and 59. Opposite the four chucks are mounted the four tool holders 60616263 secured in the two blocks 64-65 which are held by a frame consisting of the uprights 6667 (Fig. 4) mounted on a base plate 68. The blocks 64 and are laterally slidable in the interior of said uprights in dovetail guides formed in the plate 68 and the cross-pieces 6970 (Fig. 1). The motion of the tool-carrying blocks is controlled by two members 71-72 forming a double wedge which may press upon the rollers 7 374757 6 (Fig. 4) and thus separate the tool-carrying blocks 64 and 65 which are urged towards the centre by springs 77. The members 7172 are connected together by a bar 78 which is given a vertical reciprocat ing motion. This motion is controlled by a lever 79 (Figs. 1 and 2) pivoted to the axle 80, the connection with the bar being assured by a block 85 in which the bar and the lever 79 are freely slidable. The lever 79 is actuated by a cam 81 whereby the lever 79 can be moved in both directions to prevent the separation of the blocks by the reactionof the' tools during the work. The device consisting of the tool carrying blocks and the base plate 68 is slidable in a guide which is secured to the machine frame for the lengthwise motion of the tools. This motion is obtained by means of the double cam 83 mounted on the shaft 7 and acting both ways upon the lever 84 which is secured at 68 to the plate 68 (Fig. 4) of the tool-carrying blocks. The toolholders are traversed by a conduit 86 (Fig. 2 supplying oil through a nozzle upon the tool during the work (Fig. 4). The pump is driven by the machine and assures a constant supply of oil for this purpose.

The tool consists in each case of two distinct parts, whereof one 60 serves to form the point of the screw (Fig. 10) and the other 60 to form the thread (Fig. 11). The tools operate as follows. The disengaged tool advances in order to take the proper position. It then engages the blank and commences to form the point (Fig. 10), then the threadcutting tool commences to operate, moving from the top of the screw towards the point. (Fig. 11). After this operation, the tool commences a second or finishing cut, whereby the thread and the point are terminated according to the proper outline. The device for feeding the blanks to the chucks comprises two feeding recipients 87 symmetrically disposed and connected by a trough which supplies them by gravity with the blanks. Figure 1 shows (for the sake of clearness) only one of the feeding devices, and Figures 5 and 6 show details of said device. The recipient 87 containing the blanks has leading therefrom-two inclined chutes 88 and 89 ending adjacent the respective troughs 90-91 through which the blank travels in a proper position to attain the respective chucks. The said chutes consist of two strips between which are slidable the said blanks which have the vertical position and are retained by their upwardly extending heads. The inclination of the said chutes is such that the blanks will descend by gravity. A piston 92 ending in the said slides is movable and is given a vertical reciprocating motion in the recipient 87 in such manner as to collect the blanks in the vertical position with the head upwards, for the supply of the said chutes. The device is operated by the cam 93. The members 90-91 which receive the blanks individually are secured to a delivery slide 94 which is givenby a cam 95 (Fig. 5)a reciprocating motion perpendicular to the axis of the machine, the cam. 95 acting upon a roller 95* secured to the slide 94. A tappet 96, secured to the said slide, draws forward at the end of the stroke and to a suitable degree, by its action on the stop 97, a rod 98 secured to said stop and slidable in supports mounted on the machine frame. The rod 98 actuates two members 99 and 100 whereof each comprises two points in opposite position and spaced by an amount equal to the diameter of the blanks so that at each reciprocating movement of the slide 94, the said points will allow a blank to drop, which will e placed horizontally on the members 90 and 91; Adjacent the said members and adapted to be drawn forward by the slide, are disposed two push-pieces 101 and 102 (Fig. 6). The said, push-pieces are given, by the cam 103 and lever 104, a second straight movement perpendicular to the first, i. e. to the axis of the machine. This movement serves to supply the blanks to the chucks.

The operation is as follows Theblanks in one of the feeding recipients 87 are delivered by the pistons 92 to the chutes 8889. The blanks descend by their .own weight and are stopped by the set of pointed members 99 and 100 which act by their alternate motion to feed only a single blank at a timeto the members 90-91 of the feeding slide. This latter advances transversally so as to supply the blanks in line with the chucks 20 '2122. The push pieces 101102 then feed the blanks. between the open jaws 40 etc. of the chucks 20 etc. (Fig.

At this time the jaws which are controlled b the lever will closewhilethefeeding slide 94 is withdrawn. At the same time the clutch 24 engages the shaft 1 with the device controlling the chucks, and the chucks commence to turn, so that the tool-carrying blocks will move lengthwise b the action of the double cam 83 (Fig. 2). Vhen they attain the end of their stroke, the said tools, due to the action of the lever 79, will approach the blank and will begin to form the point (Fig. 10). When this cut is finished, the tools are removed, they return to the initial working position, and then begina second or finishing stroke under the combined action of the cams 81 and 83. The screw is thus finished, and the jaws of the said chucks will open and will allow the screw to drop into a recipient, while the chucks are stopped; the same cycle of operations then continues.

The outline of the different cams and of the several devices are suitably determined for the execution of the said'work.

Obviously, the said apparatus is susceptible of various modifications without departing from the limits of the invention. The details of the design and construction may also be suitably modified.

I claim: 1. An automatic wood screw cutting machine comprising in combination a drive shaft, a plurality of screw blank receiving chucks, a clutch for operatively connecting said chucks to said drive shaft whereby they will be caused to rotate therewith, a screw blank feeding mechanism adapted to deliver the blanks to said chucks, an auxiliary shaft operatively connectin said feeding mechanism with said drive s aft, means for operatively connecting said auxiliaryshaft with said clutch and adapted to operate the latter for o ratively connecting said clutch with said riven shaft operative screw blank feeding mechanism to time the operation of the latter in relation to the operation of the chucks, and means for operatively connecting said cutting tool sup orting means with said drive shaft whereby the tools thereof will be brought into and out of engagement with the screw blanks carried by said chucks.

3. An automatic wood screw cutting machine comprising in combination a drive shaft, a plurality of rotary chucks, a clutch for operatively connecting said rotary chucks to said drive shaft, an auxiliary shaft operatively connected to said drive shaft and driven thereby, cam means keyed to said auxiliary driven shaft and rotating therewith, and connecting means between said cam and clutch, whereby the latter is operated through the rotation of said auxiliary driven shaft.

4. In automatic wood screw cutting machine comprising in combination a drive shaft, a plurality of rotary chucks, a clutch for operatively connecting said rota chucks to said drive shaft, an auxiliary sha operatively connected to said drive shaft and driven thereby, a screw blank feeding mechanism-adapted to deliver the screw blanks to each of said chucks and operated by said auxiliary driven shaft, and means for operatively connecting said clutch to said auxiliary driven shaft to time the operation of the clutch in relation to the operation of the screw blank feeding mechanism.

In witness whereof I havehereunto set my hand.

JEAN FRANQOIS ARNOLD.

with rotation of said auxiliary shaft to operatively connect the chucks to the drive shaft, a plurality of cutting tools and means for operatively connecting said cutting tools with said drive shaft whereby they will be automatically brought into and out 'of engagement with the screw blanks supported by said chucks.

2. An automatic wood screw cutting machine comprising in combination a drive shaft, a plurality of screw blank receivin chucks, a clutch o eratively connecting sai chucks with said rive shaft, a cutting tool for each chuck, means for operatively su porting said cutting tools in front of said chucks, a screw blank feedin mechanism adapted to deliver the screw b anks to each of said chucks, an auxiliary driven shaft for operatively connecting said screw blankfeeding mechanism with said drive shaft, means y connected to the 

